US, Sept. 15 -- For six years, the India-China relationship has been walking a narrow bridge over a deep gorge-its foundations shaken by Galwan, its path blocked by border tensions and its future clouded by strategic distrust. In New Delhi, Narendra Modi and Xi Jinping have now chosen to step back onto that bridge.

Their meeting on the sidelines of the BRICS summit may not have erased the bitterness of the past, but it has reopened a passage that once appeared dangerously close to being sealed. Xi's assertion that India and China are "partners, not rivals", and Modi's insistence that differences should not become disputes, carry significance far beyond summit diplomacy.

But there is another message embedded in this engagement, and it i...